CVE-2025-40239

Kernel crash via uninitialized LAN8814 PHY pointer

Published Dec 4, 2025 · Updated May 11, 2026

NULL-pointer dereference in Linux kernel versions starting at 6.10 allows local users to crash the kernel via a LAN8814 PTP interrupt. The LAN8814 PTP probe can return before assigning shared->phydev, but lan8814_gpio_process_cap later dereferences that pointer during IRQ handling. Reachability requires LAN8814 hardware, unsuccessful PTP clock registration, and subsequent IRQ processing; the reported consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in Linux kernel versions starting at 6.10 allows local users to crash the kernel via a LAN8814 PTP interrupt. The LAN8814 PTP probe can return before assigning shared->phydev, but lan8814_gpio_process_cap later dereferences that pointer during IRQ handling. Reachability requires LAN8814 hardware, unsuccessful PTP clock registration, and subsequent IRQ processing; the reported consequence is a kernel crash.

The record

CVE
CVE-2025-40239
Published
Dec 4, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 4, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.10
  2. Affected versionversion=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <399d10934740ae8cdaa4e3245f7c5f6c332da844
  3. Affected versionversion=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <b093b06826b836c2824858669db080c190c04715
  4. Affected versionversion=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <da1ef8e9eb5d4a12bec32d11636e521e7d529b9e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.10; version=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <399d10934740ae8cdaa4e3245f7c5f6c332da844; version=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <b093b06826b836c2824858669db080c190c04715; version=b3f1a08fcf0dd58d99b14b9f8fbd1929f188b746 <da1ef8e9eb5d4a12bec32d11636e521e7d529b9e

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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